scholarly journals Effects of salts, protease digestions, chemical modifications, and heat treatment on the trypsin inhibitory activity of the protease inhibitor from Job's-tears (Coix lacryma-jobi L. var. Ma-yuen Stapf).

1989 ◽  
Vol 53 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Ken''ichi OHTSUBO
Keyword(s):  
Heat Treatment ◽  
Protease Inhibitor ◽  
Inhibitory Activity ◽  
Chemical Modifications ◽  
Job’S Tears ◽  
Trypsin Inhibitory Activity

Lima Bean Protease Inhibitor: Reduction and Reoxidation of the Disulfide Bonds and Their Reactivity in the Trypsin–inhibitor Complex

1973 ◽  
Vol 51 (7) ◽  
pp. 1021-1028 ◽  
Author(s):  
Frits C. Stevens ◽  
Elaine Doskoch
Keyword(s):  
Protease Inhibitor ◽  
Trypsin Inhibitor ◽  
Inhibitory Activity ◽  
Disulfide Bonds ◽  
Lima Bean ◽  
Air Oxidation ◽  
Complete Reduction ◽  
Inhibitor Complex ◽  
Molar Excess ◽  
Trypsin Inhibitory Activity

Lima bean protease inhibitor is a protein which inhibits both trypsin and chymotrypsin at different and independent sites. Complete reduction of the disulfide bonds of the inhibitor results in loss of biological activity. By air oxidation of the reduced inhibitor, full chymotrypsin inhibitory activity and up to 50% of the trypsin inhibitory activity can be regained; the rates at which these activities are regained were different. Attempts to obtain selective cleavage of one or a few disulfide bonds by carefully controlling reaction conditions were unsuccessful. All the disulfide bonds of lima bean inhibitor appear equally accessible to the reagent and with a less than twofold molar excess of dithioerythritol over the molarity of disulfide bonds, complete reduction was obtained; both inhibitory activities were equally sensitive to reduction and were lost as a linear function of the average number of disulfide bonds reduced and carboxymethylated. In contrast to this, the disulfide bonds of lima bean inhibitor are stabilized when the inhibitor is in the form of a molar complex with trypsin. Under these conditions, only one out of a possible eight disulfide bonds could be reduced in the inhibitor with up to a 10-fold molar excess of dithioerythritol. The modified inhibitor obtained after dissociation of reduced and carboxymethylated trypsin–inhibitor complex appeared fully active against both trypsin and chymotrypsin.

scholarly journals Active fragments obtained by cyanogen bromide cleavage of ovomucoid

1976 ◽  
Vol 155 (2) ◽  
pp. 345-351 ◽  
Author(s):  
J G. Beeley
Keyword(s):  
Molecular Weight ◽  
Trypsin Inhibitor ◽  
Inhibitory Activity ◽  
Cyanogen Bromide ◽  
Peptide Chain ◽  
Terminal Portion ◽  
Trypsin Inhibitory Activity ◽  
Methionine Residues ◽  
Active Fragments

Cleavage of the two methionine residues in the glycoprotein trypsin inhibitor ovomucoid, variant O1, with CNBr resulted in two fragments whose mol.wts. were approx. 16 600 (fragment LS) and 11 000 (fragment M). Both fragments formed precipitates with antisera to ovomucoid. Fragment LS retained 56% of the trypsin-inhibitory activity of ovomucoid, but fragment M did not inhibit. After reduction and alkylation, the molecular weight of fragment M was unchanged, but fragment LS could be resolved into two segments of peptide chain with mol.wts. of approx. 12000 (fragment L) and 4700 (fragment S). Each of these peptides contained carbohydrate. Marked heterogeneity was observed in the hexose and hexosamine contents of fragment L. This may account for much of the heterogeneity in neutral carbohydrate occurring in ovomucoid preparations. It was found that fragment M was located at the N-terminal end, fragment S was in the centre and fragment L made up the C-terminal portion of the molecule.

scholarly journals Effect of Temperature and pH on Trypsin Inhibitory Activity of Ethanol Extracts from Ecklonia cava

KSBB Journal ◽  
2012 ◽  
Vol 27 (6) ◽  
pp. 330-334
Author(s):  
Hee-Ye Jeong ◽  
Koth-Bong-Woo-Ri Kim ◽  
Seul-A Jung ◽  
Hyun-Jee Kim ◽  
Da-Hyun Jeong ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Ecklonia Cava ◽  
Effect Of Temperature ◽  
Trypsin Inhibitory Activity ◽  
Ethanol Extracts

Time-Resolved Fluorescence Anisotropy of HIV-1 Protease Inhibitor Complexes Correlates with Inhibitory Activity†

Biochemistry ◽  
1998 ◽  
Vol 37 (9) ◽  
pp. 2778-2786 ◽  
Author(s):  
A. J. Kungl ◽  
N. V. Visser ◽  
A. van Hoek ◽  
A. J. W. G. Visser ◽  
A. Billich ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Fluorescence Anisotropy ◽  
Inhibitory Activity ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Hiv 1

scholarly journals Ahmpatinin iBu, a new HIV-1 protease inhibitor, from Streptomyces sp. CPCC 202950

RSC Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 5138-5144 ◽  
Author(s):  
Ming-Hua Chen ◽  
Shan-Shan Chang ◽  
Biao Dong ◽  
Li-Yan Yu ◽  
Ye-Xiang Wu ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Inhibitory Activity ◽  
Streptomyces Sp ◽  
Hiv 1

Ahmpatinin iBu and statinin iBu, two new linear peptides, were isolated from Streptomyces sp. CPCC 202950. Ahmpatinin iBu exhibited significant inhibitory activity against HIV-1 protease with an IC50 value of 1.79 nM.

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